Gyroscopic gun sight



Oct. 7, 1952 H. K. WEISS 2,612,692

GYROSCOPIC GUN SIGHT Filed July 14, 1945 3 Sheets-Sheet 2 Herb Ejt KAAEISE aammwwmu GYROSCOPIC GUN SIGHT Filed July 14, 1945 a Sheets-Sheet 5 portion to the angle of elevation of Patented Oct. 7, 1952 U VGYROSCOPIC N SIGHT Herbert K. Weiss, ElPaso, Tex, assignor to the 3 United States of America Secretaryof War as represented'by the Application iluly 14, 1945, Serial No. 605,174

1-9 Claims. (eras-19) (Granted under the act of March 3, 1883, as

it i 1 The invention described factured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon;

In my application, Serial No. 560,831, filed October 28, 1944, now Eatent 2,476,'342, dated July 19, 1949, I have disclosed a gun sighting mechanism intended for firing at moving targets. This sight includes deformable and pivotal linkages by which a'triangle may be set up or simulated. The first side of this triangle represents to a fixed, predetermined scale, the slant range of a target or, approximately, the average velocity of the projectile multiplied by its time of flight. This value istaken as constant at the most advantageous range at which the particular type of gun is adapted to engage the enemy. The mechanism is so attached to the gun that the aforesaid first side of the triangle is at all times parallel to the bore of the gun.

The second side of the triangle is adjustable in length andis pivotal at its intersecticnwith the forward, or muzzle end, of the first side. This second side represents to scale the speed of the target multiplied by the time of flight of the projectile. Connections to this side are provided so that it may be maintained substantially parallel to the path of the target.

The third side of the triangle is adjustable in length, in accordance with the adjustments of the second side, and represents the line of sight to the target. A sight is so connected with this third arm as to be at all times parallel thereto. Thus, as the second arm is properly adjusted in length and direction, so that the intersection of the second and third sides represents the instantaneous target position, the gun is given a deflection or lead such that the projectile and target will arrive at the same point at the same time,

matically by means of a neutrally mounted gyroscope having three degrees of freedom, and so mounted upon the gun that the third degree of freedom is constrained to rotation by and in prothe gun, as will be subsequently described.

It is therefore an object of my invention to herein may be mane amended April 30, 1928 3'10 0. G. 757) provide a novel mounting for a-gyroscope, together with meansoperated thereby .to indicate directly the angle of approach or departure of an object relatively to the location of. the'gyrdscope, as the gyroscope is moved about its third axis=of freedom so as to maintainits second or precession axis in ,a vertical plane through the gyroscope and object, while at the same, time ro tating'said axis in said plane by anamount proportional to the elevation of a line between the gyroscope and object.

More specifically, it is an object of my invention to provide a gyroscopic device so associated and related to a gun, that the gyroscope will precess from a predetermined position, by an angle proportional to or equal to the angle of target and point of impact triangle is simulated Figure l 2 to scale and automatically maintained in proper size and relation to the gun so long as the target speed remains constant;

Astill further object is to provide a mechanism as outlined in the preceding paragraph, wherein the said triangle is utilized to maintain a line of sight in proper angular relation to the gun to eifect a hit as the gun is moved to maintain said line of sight upon the target.

Another object is to provide a mechanism in which a triangle as aforesaid is automatically maintained correctly adjusted by a gyroscopaas the gun is moved to followa target.

A' iurther object is to provide a gun sighting device having a lineof sight positioned relative- 1y to the gun bore by a mechanism setting up and representing the gun position, target, and point of impact triangle, wherein said triangle is adjusted automatically by means of a gyroscopically-controlled follow-up, as the gun is moved to maintain the sighting device upon. the target. Other objects andadvantages will be apparent on study of the disclosure. 3

In the drawings:

.Figure l is a schematic view showing one construction for combining a gun and gyroscope to carry out the basic principle of the invention,

is a three-dimensional diagram showing the factors involved in the theory of operation of the invention,

Figure 3 is a diagrammatic view showing the relation between the gyroscope and the gun for several positions of gun elevation,

Figure-4 is a perspective View of a complete assembly of gun, gyroscope and resolving mechanism, together with connections therebetween. I Figure 4a is an enlarged detail View of the follow-up control and differential of Fig, 4,

, FigureAbi is "an;enlarged-sectional view oira -suita-ble form of" damper for use with the gyroscope,

Figure 5 is a view of a modification of thee construction shown in Fig.4, WhGI'GiHHi/vPOWGIE- fdriven damping mechanism is employed, and Figure 6 is a view of a modification using a still different form of dampingmechanism:

' In the explanatory diagram of- Fig. 2, the

4 is wD cos p is obtained by dropping a perpendicular from F to the horizontal plane at T5. Thus the aforesaid horizontal component is a. multiplied by the distance GT5 or uD OOS p. Thus o'DfgOs-pwl) cosy or a cos p= w cos 1/) (2) From Equations 1 andlZ'it is possible to obtain the angle 4/, since the quantities upon the lefthand side of both may-be measured in the trackvarious points angles and :angularwratess.arezq identified by the following symbols: P--actual target position at any time t,

CB-target path.

Fpredicted future position-corresponding to P, or the point at which the projectile and :target .willgmeetz- I Ger-gun position;.. l

I s-sneedof target along p ath S+distancefromP to F, equalto Stpi:

. -elevation angle. of v 'sla-ntz plane vel'ocity 3cmponentx D'leng.th of'line GF 'or future predicted/range.

. The. slant planejocez"; attains. the, line Q GF I connecting the gun with-the predictedgpositiona;

F, Thegun is;positionedffto ,point, .at..F by, rotating ,it .in a, horizontal ;.p.1.ane..to; an azimuth angle 6 and then rotatingdt' in, a ..verticalf.p,lane

"about a horizontal axis 'togapredictedgangular elevation. As .the gun,'m oyes touconti'nuoluslys maintain a properqposition' in,advance ,o fj the target, 1 the. angles, 0 "and change. at, the ,rate's a and B, respec'tivelyj,j

The, line, GFfmust always cross extrapolated target path" PFBv and f' therefore. rotates, aboutGvwith an. angular. velocity w, ,while remaininetin, the slantxplaneG'CB. The.com-

ponent. of linear velocity oi ,point 1 F in theslant plane, measured perpendicularly, to the v,li'ne,v GF

is,,.,then, wD'." This componentwD'jmay,be..decomposed, into vertical and ;.horizontal; componentsasiollowsw AtJFLDass a. .plane .perpendiculantoNGF. This plane ,cuts .the. slant plane. ,in,.a,, line ..1?T1.'...,the horizontal plane ..through' G"fin a line. TTiLsnd thefl vertical, plane through. ,GFI' in a. line. F'I'z. The. vector. representing, the angular velocity w is an extension of line Fri, and makesihe angle with ahorizontalvector, which angleappears in the diagram as ,T2TiF.I. l

The horizontal component of; wDj is gthi'en, wD cos 1/. The ,vertical componentjis'itheuvertical angular. ,rate, of movementl-ofg'line GF,"..multipliedby ,the length .01. ,GEiQrDZLJIhatJis.

pD"=wD"s'in"1//; or sa-sin h (1) To obtain a similar-expression for; azimuth rate, it will be notedthat-'azimuth-raterisrmeasured about a vertical axis and that thewmagni- "-ingc process.

However, this is not the course angle used for sights of the type herein disclosed-. cItzisgsuflicient for the present development estate that the heading which must be determinedior the sight disclosed is that of'a'" horizontaljline =through F which also lies .in the slantplane. This heading is shown in Fig. 2

as'*the li'ne FA. Since this line is horizontal, it

I isrxlesirable tosreferits heading in a horizontal .planecto somez'convenient reference line in that plane, such as GTsTz, the intersection of a verticaLplane thr0u h -.GF;lwi-th. the horizontal plane throu'ghsGg. If,a-line.T2Ta parallel to FA is drawn through; T2 and: a perpendicular isv dropped from Gto TzTa intersecting. T2T3 atTs, the anglelTgGTz defines the heading. of T2T3 and hence, of,FA=, Thegahgle .TaGTz will be identified as at .and since, itdsQalsoan azimuthangle of GT2,

measuredgwith respectito aflxed reference-GT3,

the rate of changeqofj:isequalto a, the rate. of

o rang'ular movement of .thegun in. azimuth.

Now throughkF, drawgline FT4 so that it is horizontalr-and in plane TiTzF and so, by con struc.tion,-p arallel.to linefIiT z. Since plane T1T2F was- ;constructedgperpendicular.to GF, the angles GETsandGEIz areb oth right angles. Also, since FTs-islhorizontalsandFIs is-vertical by construction,.-theangler'l FTs is a right angle. Thus TiFis perpendicularzto -plane FTzG, being perpendicular:to -two nonparallellines in said plane, so that-,Tgli-flzis a: right angle. Since T1T2 is para-llel- ,to-' T4E,-,angle .TiTzF isa right angle. Also-,: since 5GT2 flies; in -,p la-ne T2F.G, angle T1T2G is:-' a right {angle-s There are thus established .th-ree right triangles whose vertices' are G, F,

T1 .a lti'rmg 1 Lines AR and GT1 are parallel, both being horizontal and con-tained inthe same slant plane. Thus GT1 is parallel to TzTs and, from the similan, right trianglesfGTzTa and .GT2T1, the. angle G'T Ti:=6.

In triangle T1T2F,-,v

Equation 9 sl1 gests';that by properly connecting a gyroscope to train and elevate with the tude of the horizontal component'of @D, that y gun,- that-angle amaybe directly obtained there- 5. from provided it can be subjected to a rate of angular movement equal to a sin 2p.

Figure 3 shows basically how such a mounting may be effected. At position A the gun is horizontal and the gyroscope has its spin axis parallel to the gun bore. At position B, the gun has been elevated 22 while the gyroscope spin axis has been turned in the same direction by twice this angle or 45. At positionC, with a gun elevation of 45, the gyroscope spin axis has been turned through 90. This relation is maintained throughout the elevation of the gun, so that when elevated 90, the gyroscope spin axis has been turned 180". Thus the precession axis of the gyroscope is at all times turned through twice the angle of gun elevation to satisfy the requirements of Equation 9..

Referring to Figure 1, G indicates a gun of any type or calibre, mounted in a cradle C carried on trunnions T, only one of which is shown. Said trunnions are carried by supports S. fixed to a trainable base B. One support S is formed with, or has attached thereto, a gear segment I concentric of the axis of trunnions T. A bracket 2 is fixed to the side of cradle C and has a sleeve bearing 2a journaling a shaft'3. Said shaft has a gear 4 fixed on its inner end and in mesh with segment I. As indicated, the pitch diameter of segment I is twice that of gear 4 so that the latter rotates at twice the rat of elevation of the gun. Shaft 3 has a fork or yoke 3a on its outer end. The fork mounts a gimbal 5 for pivoting about an axis lying in a vertical plane parallel to the gun bore and which is preferably horizontal when the quadrant elevation of the gun is zero. Gimbal 5 mounts a gyroscope rotor 6 for spinning about an axis normal to its own axis. A damper I that may be of the type shown at Fig. 412 has one element secured to gimbal 5, and another secured to the adjacent end of yoke 3a, whereby pivotal movement of ring 5 is damped. At the end opposite damper l, yoke 3a carries a dial 8. over which moves a pointer 9 fixed to a trunnion rotating with gimbal 5, whereby the angle of movement ofgimbal 5 may be determined. Thus it will be apparent that, as the gun is elevated, the axis of gimbal 5 is likewise elevated, but at twice the angle of gun elevation. In accordance with the principle of my invention, combined train and elevation of the gun in following a target, causes the spin axis to precess about the axis of gimbal 5 through an angle equal to the angle of approach of the target, as will be more fully explained in connection with Figure'4.

Figure 4 shows one embodiment of the invention wherein l0 indicates a section of a large gear fixed to the gun platform and whose center defines the axis of train of the gun G. A gun carriage including trunnion supports S is mounted for pivotal movement on the axis of train. These supports have bearings at their'upper ends receiving the gun trunnions T, only one of which is shown. It will be understood that the gun cradle C is provided with conventional gearing by which it may be elevated about the axis of trunnions T.

A bracket II is rigidly associated with and extends from the side of one trunnion support S to provide a bearing l2 for a train shaft |3 having fixed thereon a bevel gear i4 and a pinion IS the latter meshing with platform gear A training crank I6 is fixed to an axle I1, journaled in bearings not shown butwhich may be carried by bracket ll. Axle carries a bevel 6. pinion l8 meshing withgear |4 so that, as crank l6 is'turned, the gun is pivotally moved in train about the center of gear H].

A sleeve bearing|9 is fixed to the top side of cradle C and journals a shaft 20 having fixed thereto a gear 2| and carrying a semi-circular yoke 22 at its outer end. A bracket 23 is bolted to the side of carriage C and has a bearing journaling a shaft 24 that has a gear 25 fixed to its outer endand a link 26 secured to its inner end. The axis of shaft 24 intersects the carriage C at a point 24a. Gear 25 is twice the diameter of gear 2|, for a purpose thatwill be explained later. A second link 21 is pivoted to the end of link 26, as at 28. Link 21 is also pivoted at 29 to gun trunnion support S; and the connections are such that the axis of trunnion T, pivots 29, 28 and the axis of shaft 24, projected upon a plane normal to the trunnion axis form a parallelogram. Thus, link 26 and a diameter of gear 25, remain vertical for all angles of gun elevation, and gear 2| rolls about gear 25 as the gun is elevated, to rotate shaft 20 and yoke 22 through an angle that is at all times equal to twice the angle of gun elevation. The gyroscope'includes, in addition to the yoke 22, a ring 3|! that has trunnions journaled in the ends of yoke 22 so that ring 30 may pivot relatively to said yoke about an axis that is normal to the axis of shaft 20. Ring 3|] has bearings 3| and 32 defining an axis at right angles to its own pivot axis and journaling the axle 33 upon which rotor 34 is fixed.

Any suitable arrangement may be used for spinning the rotor. For example, therotor may be simply the armature of an electric motor having the desired moment of inertia with well known means for leading current in through the trunnion axes. I have indicated schematically at 35 a motor having its field coils fixed to ring 30 and its armatureor rotor directly connected with axle 33, together with current leads 3G. It will be understood, of course, that ring 38 and all parts carried thereby, are balanced so that their center of gravity lies at the intersection of the three concurrent axes, previously mentioned.

One trunnion of ring 30 has the rotor of a telemetric transmitter 31, secured thereto,'the stator being fixed to yoke 22. The other trunnion of said ring has one element of a damping device 38 secured thereto. As shown at Fig. ib this device may consist merely of a casing 38 fixed to yoke 22 and having a series of centrally apertured spaced plates 38a secured therein and be tween which are mounted discs 30a, fixed upon trunnion 30b. The casing 38 is filled with a suitable viscous liquid, such as oil, whereby rotation of ring 30 relatively to yoke 22, is effectively damped. The rotor shaft of transmitter 31 may project through the end of the casing and have there attached, a pointer 39, movable over a scale on the transmitter casing to indicate the angular relation between the planes of ring 3|) and yoke 22 or more specifically, the angle of approach of a target.

The aforesaid angular relation is transmitted by 31 through a flexible cable connection, to a repeater 4|, mounted upon a platform 42. This repeater has its rotor shaft connected to an arm 43 '(see Fig. 4a) having a contact trolley 44 pivoted at its distal end. A shaft 45 is journaled in suitable bearings on platform 42 and at its end is provided with an arm bearing an arcuate surface 46 concentric with the axis of shaft and having two contact portions, separated by a narrow strip of insulation. A follow-up motor 41 ousnfronn, inspection; of; the; circuit 1 includin a d fferentialfiiihmmeans-.-'o:a:;worm:50; andgear 49in Thehot, or i e: tsaid: difierentialiissconnested t beidri-venfromzshafii li as bysmeans il -a; flexibl shaituelement: .41;, 'Iflietcentemp lanetarwofa-said."diiter ntial is connects -t drive flexib1e;shaft ;elementi55.=;=by;,:means ;of; rin ssa-nflaand iazxpi onfi CQIlmBQtedjtO -shaft 355.61: Thus-, the:de ree:f rotation s fiflexiblsztdrireefi wprop rtional to the-al ebr ic:z umztofzhsirotae ti nstofr. motor .4! and: thesanelerof tra-imofithe un-a This; purpose-;.-of:. hisswilli. .bevwub equently explained. I 1- Aibracketvil 1-isqpivota1ly-mounted unon=:thei ;un cradleabytmeans: ofa: bearingr-zsleevets This braokethas aslinhzflzatrits;endadiacentzthei un cradle-xthatv-is QiYGIgQflgt li nlg;;;2 -.WAs;the.-.,ifetztiyie l ngths-5 fr'linksi 2 6t and-1159" arerthe same; link; 5.9 nd.;;.bracket 5:1 5 are maintained qin-ifixedw-ran ular re atiomtomh I orizontakplaneafonallansksmf un-,.el eyationav Bratzhet:v iszshapedz at. tsrifre orr-outenend, torsuppoztsa d-journalzthe v r elementS:- of ;on.e;-sportio.n ofi the:.resolvin r fiYice As. previously: stated;thisnres lv n device {is constructed :to; set up ,:to;;scale1;-a-; triangle, a2: first side TOfE which: iszfixed insleng hz and: rep ent thejproduot of thetime of flight ofithe projectile foran-,-average: assumed :slantmangeland :its ave-re age,vel,o cityf\: r; ;thatrrangerv Thisxfirst side is maintained,zat.-.allztimesrparallelrm the gun bore The second side; pivotallysjoiningzthevforward end; of; thewfirstsid r presen s c h -,:product :of the-:timerofiifiig'hti ofrtheiprojectile; s'ga'foresaid; and the; average "V103ity' o--- theatargetzduring that time-,:-;in:;other w0rds-,- .th e;distancerthatcthe target traVe1S'frDm the-time the-projectile rleaves thes-ununtil-itrhitsnthe target-d Said second side s :represented by :an zarnnfill pivoted on; angaxis on theouter-rendiof bracket 51'. This axis is; maintained y r-ti ali ythepreviousl describedrparallel gram linkage-:flxetch Arm: 60 is; a taohedv oaza arrfi la; forming; one isidrofx difierential,.sgenerally rldentifiedcby :theanumeral 611:. G rr-filas'meshesrwith nd?isrdrivenhbw worm -62 ioonnected 130 fiefible shait;element:155i Thet-otherl-side: -Tv fi BEBnt flLYB'l s az ar ,6lb; pivoted 1 1135 bracketst3xandninzmeshzwith:axworm 64, & cotiller-stead, to (be rotated {by a; flexible shaft driver-65.11. 'I'herother enchant the aforesaid drive s: .jqumaled ,in ..a;sbea1 n late.- 66 secured -to platform Al-randfadapted,tob srotatedtby a-hand: wheel: 61 having engraved, thereon-:2 a scale-0f target speeds 61a. This scaleeissread-tby'means ofiapointer fixedz totplatewfifia The center.pLdifierential: 61,: issrepresented by a iplanetarywgean :6 i c mountedaupon-ian :arm: exnding .rad ia1ly of--..aicentralishaft thatextends ddwnwardly through ear, 6 Id and arm Swami thereucarriesa beyel, pinionjld, A screw shaft 68 is, j ournaled inbearings defining-anaxis parallel toarmjfli. This shaftLatJits inner end, carries a. beyeLpinion.58a;.,in.mesh; witn,pinion tilde. A

' nut 69, isthreadd, uponshaft. 68-,and;has pivotally connectedfithereto one section Ifla, of a telescopingrrodzlfli; Theeothensectionkfl 0b:-of;.said rod telescopes withinzseotionr 'lfldzatrone: endrand hassarzpivot PiD1i0tfiX8d1b01gi1JS :other end; This pin-his zjoumalled -in.:aibearing formedzby a;mem.: berz'lj'; having; a,fiange 1 la," pivoted to a-zflanged element 121 omiplatform 42: The: axis, thuspde-t fined: .iswpemendioulargto the; axis of; pin 11 0a..

, Pin-i'lflmprojects upwardly-from the bearing 'in flanged member?! I and has;fixed thereto, a sleeve 10d :withimwhichtfits;a;sighting device suchzas telescopei'l Any otherwell known sight may be used, 1 itjbieing'ressential lonlyrthat gthe line 1 of sight"; determined? thereby remain: at all times parallelzto -.ro.d;10'. V

The;- operation:;of=- my: invention: will now: be clean- Withallielectrioalaparts.;energized;and the gyroscope spinning, rhandwheeli 61 is, turnedto indioaterthetknown or estimated speediofra-targets to they. engaged; An drive": is thus: effected throughxfiexible shaft GELWOIHI'L 64; side 61b and center: 61c: ofidi-fierential ;B.-l a throughgears; 61 d andr=68.a;1to shaft.;68.:. The;parts-are:so propora tionedrgthatr; nuts 69.? will be; thereby translated a-longzrshaftififlrz until: .th e distance of: the, pivot axisv Of'tIOdQ'I 0* upon: nut 69 "from the central axis ofrdifierentiali 6| }wi-1-l-v represent :to: the; predetermined; scale; the; productarofz. target :velooity and time of flight of .projectile The parts gate; so connected; and: proportioned: that the distance between-zthe pointiofzintersection of -the-zaxiszsof shaft 68,-; with?v the normally ,ruprighteiaxis'; of difrlferential-ifi Ir, and thepoint :ofzintersectionbetween thetaxiss ofzjpin TUCiEaIId the; axisgofgfiange-Jla; remains.zconstantiandsubstantially-p elftoxthe gun bores Thiszdist-anoes of {001E565 represents to scale thefixedwrangeszat-:whichij the;-target is. usne ally engaged? Thereiore; when armiVBOY iSv'iSO turnedgasctoxbe parallelqtorthe actual path of:,the targe.t,-:.the.=third:side of :;the triangle; as material? ized;by rod-10;willfindicatathe:lineof-rsisht alon which-the target-rshouldtbe viewed whenrthe gun isi=fired.

Asa-the gun-sis elevated: gear; 21 rol1s?:ar.ound seam-215i anduielevates-uthe; precession axis of. the gyroscope atztwice '.=the angular rate of the; gun itselifla.v Other: factors remaining; constant, the angle of "precession ,of the spin axis about: the axis .of rringzz3flriwi'llbe proportional to;therati0 of ratemf "elevation tot; rate-oftrain. of :theagun, dividedzz'by the sine of ,twice: the gun: elevation angle; Thisaof course; assumes-thattheigunzis continuously 'trained' and elevated yin the: man;- ner necessary'xto :keep: 'its zlin'euofi' sight :continur onsly :upon the; target:

For example, with a target-.idirectly'"incoming son-that.1:1;(1;v the:angle;zof approach; is zero and thengyroscope preoessesnntiliits axis":is-.pa-ral1.e1 toztheetrunnion-r axis: withaitsatopza n i y,zto;- wardrrthesgun; Under this-.condition, the farm fiflicwillbealiemdwith.ithe first side-toftheatrie an le; parallelto:thesmboreand vpointing; a y from' ;the ,--telescope:u As :armismaintained horizontalJonallangles;ofigyn elevation-sit: will be ;noted.-that :thexlineof sight is ,moved into a vertical plane, parallek to; the-.-. gun bore; but making ,an angle therewithmthatilies below,the bore. Thus, to hold the sight uponqtheatarget, the gun must be; elevated socthat its.v trajectory liesrthe, propen distancein advance; of theqtarget.

Likewifierin the case of a...-,di,reotly,outgoing target, a. zero and, thegyrosoope.willprecess until :itsspinaxis is ,paralle1.to the. trunnion,- axis with its ttop end ,away fromuthe. gun. Under this condition, the. connections are suchthat the arm 60 M111 begaligned with theifirsttside of thetri:

angle, parallel to the gun bore and pointing toward the telescope, whereby the line of sight makes an angle with and above the gun bore, so that as the line of sight is held upon the target, the gun is properly aimed in the vertical-plane of, and below, the target.

These limiting conditions suggest the manner in which the instrument is to be calibrated. For

allel to the gun bore and pointing in one direc- I tion, when the spin axis isparallel to the gun trunnions with its top end in one direction, and in the same plane but rotated 180 when the top end of the spin axis is'parallel to the gun trunnions with its top end pointing in theother direction, The particular relation will depend upon the direction of spin of the gyro rotor. For all intermediate positions the arm is correctlypositioned, and in accordance withEquation 9.

As ring 30 pivots relatively to yoke-22, the angular movement is detected by transmitter 31 and repeated at instrument 4l,-thus rotating arm '43 and trolley 44 accordingly. As soon as trolley 44 moves oif the insulated portion on element 45 and onto one or the other of the live segments, follow-up motor 47 is energized .to rotate in the proper direction to restore the'insulated. portion of element46 to contact with trolley 44, by means of gear 49, a first side of differential 53, ring gear 53a, gear 56, shaft 55a, and gears 56a and 4911. In addition to the control of motor 41 by trolley arm 43, trainingof the gun bymeans of handle IB' correspondingly drives flexible shaft 54, a second side'of differential 53, ring gear 53a, shaft 55a, and gears 55a and 49a, to rotate shaft and. sector 46.1 Thus both sector 46 and trolley 44 rotate at gun azimuth rate, the former because'of the connections just described and the latter as a result of gyroscopic motion according to Equation 9. This arrangement permits the motor 41 to set in the proper orientation of arm 60 initially, after which it stops, while the drive from the gun both rotates the arm 69 properly andmaintains the neutral sectionof sector 46 on trolley 43 as said trolley rotates at gun azimuth; rate. The action is smooth and continuous so that shafts 45 and 55 are at all times rotated in exact.synchronism with the precessional movement of gyro rotor 34, and motor 47 operates toisupply the excess or deficiency of movement of sector 46 necessary to effect such synchronism over the movement supplied by way of the drive from flexible shaft 54 to shaft 55. i i

Differential Bl is a conventional take-out deviceand is provided to avoid erroneous adjustment of nut 69 that would otherwise be effected by pinion 68a walking around pinion Bld, as arm 60 is rotated. By the construction shown, actuation of drive 55 to rotate arm 6i), causes the center of the differential to rotate pinion Bid by the amount necessary to maintain screw shaft 68 motionless. Thus speed settings are unaffected by pivotal adjustments of arm 60 and such settings are determined solely by rotation of handwheel 67. i

The purpose of damping device 38 is to prevent the gyroscope from rotating'or responding too rapidly in response to angular movements of the gun and causing instabilityin the circuit together with excessive hunting. ofnthe follow-up motor. -It is clearthat a damping value should be; selected that is small enoughto allow the 10 gyroscope to respond to true angular rates but, at the same time of sufficient value to prevent instability and excessive hunting.

An alternative damping mechanism is shown at Fig. 5 where a number of parts are duplicates of the corresponding parts used in the construction of Fig. 4 and are identified by like reference numbers so that it is considered unnecessary to describe them in detail. The damper 38 may, in general, be of the same disc-in-oil type, as used in the construction of Fig. 4. However, while the discs 3ll'a may be secured to a trunnion 30b of ring 30, as in Fig. 4b, the casing 38 and its plates, are aifixed to the rotor shaft of a repeater15 fixed to yoke 22, as by means of a bracket 76. A transmitter ll of any wellknown type, has its rotor driven from follow-up motor 41 and is connected to control repeater 15 by standard three-phase connecting cable 18. In this manner, the damping action is transferred to the follow-up motor 4'! so that only a negligible resistance to rotation of ring 30 exists when motor ll is at rest. However, because of its rapid rotation through geared-down connection 49 and 50, motor 47 exerts a large torque on ring 30 so that said ring is effectively damped while able to respond at the proper rate to precession induced by the gun rates in following a target.

The general construction disclosed at Fig. 6 is the same as used in Figs. 4 and 5. However, instead of providing damping means directly associated with gimbal ring 30, I have mounteda damper 19 directly upon the shaft 41a of followup motor to thereby reduce the initial acceleration and top speed of the motor. The inertia thereby added assisted by the moment of inertia of the rotating parts of the motor 4'! and that of its shaft 41cc. Depending upon the value of the total moment of inertia found necessary, an inertia wheelmay be added to shaft 41a. When the inertia of damper I9 is found to be too great, the inertia of the rotating parts of the motor only may be suiiicient. Thus, when the tracker makes a sudden correction, the gyroscope attempts. torespond, but is restrained by the damper in the species of Figures 4 and 5, While in the species of Figure 6, motor 47 is restrained. The effect of the trackers sudden corrections upon the position of the gyroscope and arm 60, is thus minimized and the response at all times closely, approaches the true average of such stepby-step corrections as the tracker may introduce. Thus the action is smooth and continuous and arm 60 is at all times positioned at the angle of approach or departure of the target relatively to a vertical plane through the gun bore.

In the claims, the term resolving unit means the arm 60 and parts carried thereby, together with rod 10 and connections to arm 68.

While for simplicity of explanation I have shown my invention as applied directly to, and operated by, movements of the gun itself, it will be appreciated that such a mechanical tie-up between the director and gun is not necessary. It will be obvious to those skilled in the art that the triangle-simulating mechanism may be entirely separate from the gun and connected to have its several parts adjusted with the gun, as by electric, pneumatic or hydraulic repeater connections. Furthermore, the parts of the trianglesimulating mechanism are not required to bear the exact relation to the vertical and horizontal as shown inFigure 4. Any system of Cartesian coordinate axes may be chosen to represent the vertical, andmutually normal horizontal axes,

111 and so- 1ong,as-,lthe parts;-of ,-.the mechanismare adjustedwith relation tog-these chosen coordinate axes, in the same manner-ast-thecorresponding parts of' Fig; 4- are ,adjusted with respect to the actual correspondingruertioal and horizontal axes, the ,devicerwillsoprate as Hand-:for its intended purpose, and"theangle btweenthe sight-line side of the triangle and the part ,.representing -.the gun can then be transmitted to correspondingly adjust the actual ,sig-htrelativflly -touthe real-gun.

{Having now: ful ly-;disc losed my invention, what I Claim and idesire to 8Q I -byLetters Patent -is:

'1. Incombination wi-th-1means operable to ,angularly -move *a gun ginj-train and elevation, ta gyroscope including gfirst means mounting the firstsaxis normal; saidrspin axis and second means .mounting; and iirst means :for mivotal movement about-a sec axis norm aPto said'first axis, said .second axis being parallel to -the axis oheun e vatiqa -and'. th dwmeans synchr nously op a ed es ons rto a tua io of sai i unwelevation means torotate-saidsecond means: through an angle equal, to 1twotimes thei-angh;,of gun ,elevation.

--In combination*with aieunavinameans to ra and el vate t; reema- 'l yroscopearotor. firstmeans mountin said: rotor {for imovement about a; first--,axisnorm al ;-;to -;lts s pin-=axis, second means mounting said first means 'for :pivotal movement sabouha second uaxis normal i to "said first ==axis and;parallel rto the ,E-elevation ,axis ,.of aid :sun. an mean zpo itively operated; in:-response to: actuation; of saidgun elevation :means, to synchronously rotate said? second means :and first axis, about said second 81Xi5, through an angle equal to ,twice the :angle f ,-gun -elevation.

"3. I-n-combination withrza gun movable in train and elevation, sighting means for said;gun;movable with .saidlgun and-angularly adjustable relatively thereto, a gyroscope 4 including first means mounting the "spin axis of said-gyroscope:for precession about a .first v.ax-is maintained in "a plane ,pa-ral-lel to 331 =vertical;p1 ane through "the bore axis of. said gun, means for-angularly moving said ,first means: to rotate said; precession: axis through twice the angle of gun elevation, and means responsive -to {the precession :of said gyroscope about-said firsti axis to angularlyzadjust said ,sighting means relatively @to ,said {guns '4. -In a gun-directing mechanism ;for ra ;gun movableintelevation and train, a --resolving;;unit comprising -a pluralityof ,pivotall y mounted, ;int'erconnected .armsiadaptedtome-adjusted todefine to scale ,a .fir'st,point representing: gun-cposition, ,a second lpointrepresenting target position at impa and a-th rd: intren esentin mresent target position,}means maintaining-a line through said v.first and second points parallel .-to the gun bore, gyroscopic-means ,precessingdn responseto change of elevation of thegun and means controlled by said precession ,to maintainsaid-sec- 0nd and third pointsparallel.totheactualtarget path, me'ans.- adliustingsaid thi int;relatively to ysaidsecondnoint by a distance proportionalto target. speed, andlsishting imeans having .itsline of sight determined Z b y a .line connecting said first'and third points. 1

'5. In a gun directing instrument, -a-gyroscope mounted to process about. an waxislying in a plane parallel to a vertical',planethrough the gun-bore, means'operable to elevate saidaxis'through twice the angle of gun elevation, a ,resolving :unit 'including an arm'upivoted ,to .move about a vertical spin axis ofsaidygyroscope -for precession about a elevation.

l to isaid first .-axisrmeans connectedmtor dampo'rel ative angular movement 'ibetweemsaidzfirst second, means aboutssaid k'firstriaxissaand: means operable-;-to'rotateisaidirsecond means ahoutzsaiid' second axis, to synchronously I ielevate fsaidrinrst axis mt aerate equal ato ltwloe sthe :ratecofsgam 7. In a-igundirectingznnechanism,ibazgyroscnpe mounted .in oneutral' -zequilibrium, rincluding: first means {mounting rithe :rrotor :of ssaidrzgyroscope for11lpivotal:.:movementsabout2a firsteax-ismormal to its .t-spin axis andssecondtimeans'zmountlng said first-meanslionrotatiomazboutoa second aids normal ;to rsaid firstraxisa alhsaidmxesrheing current, ei-means mnerabiarby and withigunr elevation otoiirotatessaid seconii about :said second axisi' at amateieqmal ito rtwice the irate :of z'gun ielevation,ralfolloweup ifzmotor, connections slresp'onslve l'to p'recessi on ifof new gyroscopewaboutisaidi' llrst iairisfioperahle' to trolisaid moto'nimnd dampingmeanshavingrelatively 11c)totalale fi 'arts, one part being conned-ted to :sai'd flrstrmeans an Iwsecona. part conn'ecteli to be actuated by'sa motor. v y

:8. In 'combinatlon with a gun having train and elevation i axesa resolvin means "defining' a triangle havi'ng afirst side maintained ara1-1e1 to' -tlie bore 'of said-gun,-'an arm l representing a second side and rotata'ble on an zaxis passing through meander said lirst side, means ito maintain asai'daxis substantiallywertical, fa part adjustable *alor ig- -sai-d -arm in mm portion? to itargetwelocity, a rod initiated to 'sai'd part :and "the other' entl df sa'id first siiie, a'

gyroscope mounted Yto izprecess about an lying :in Ha plane normal tobsaid elevation aids, means .lto :elevatersaid precession axis about an axiscparallel"tozsaidselevatiommissynchronously with zand cat twiqe' ithe Jr-ate '01 Felevation rot. said zgun, 'va' difierentiall, follows-up? means con trolled by zprecession rot saidsgynoscope :to diperate cone :sside tofrsaid' :dilfe'ne'ntial, :lmeans aresponsive to training of said gun to operate the other -.'si. de of said w'lifierential, means :driven Lby the center :of saidzdiffierentialztoa'otateksaiiisarm, and i a sight :mounted in spredetermined :angular relation withzsaidfrod. 4

9.- In combination with s-a. gunzihaving awar riage. mounted torztrainingrabout asubstantially vertical axis, "and :said gun vb'eingimounted ctor elevation about .:.trunnions defining assuhstantially horizontal :axis :and rsu'nportzed .znn rsald carriage, a first, -hracket rfiXed :to maid ":carriage, a :second 'bra-cket .zpivote'rl tonisaid :g'u'n on an axis parallel to said trunnion :axis, an arm pivoted on said @second ibmcket'i'dnl alh 'axis normal to the axis: of :said second fiaraoketimeans maintaining athenaxisarofssaid armmarallel 'to- 'the train 5 axis of said gun, a .rscrew lzshaftfij our'naled on :and along /said TmmJa nut threaded on sa'l'tl shat,:.an:extensibleiroddiavinginne endlpivotally connected with :said irnutez-and Elts iutherififlqmp versally pivoted on said first bracket, gyroscopicxmeans mounted for precession about an axis in a plane normal to said trunnion axis. means operated by elevation of said gun to revolve said precession axis in said plane by twice the angle of gun elevation, and connections responsive to the procession of said gyroscopeto rotate said arm.

10. The combination as specified in claim 9 and a sight connected to have its objective optical axis maintained parallel to said rod.

11. In a gun directing mechanism, means simulating to scale a triangle having a first side of fixed length and maintained substantially parallel to the bore of a gun to be directed, and a second side pivoted at one end to an end of said first side and having its effective length adjustable in accordance with the speed of a target, means mounting said second side for rotation about said one end and ma horizontal plane, a sight line device connected to remain parallel to a third side of said triangle, a gyroscope having a precession axis normal to its spin axis, said precession axis lying in a vertical plane parallel to the vertical plane through the axis of the bore of said gun and connected to be elevated in said plane at twice the rate of elevation of said gun, and means controlled by precession of said yroscope to correspondingly rotate said second side of said triangle.

12. In a gun directing device, means simulating to scale a triangle of the gun position, present target position and future target position at the point of impact of aprojectile thereon fired from said gun, the side of said triangle determined by said target positions, being adjustable in length in accordance with target speed, a gyroscope, means effecting precession of said gyroscope in accordance with a combined function of train and elevation rates of the gun, and means responsive to precession of said gyroscope for pivoting the side of said triangle determined by said target positions.

13. In combination with a gun, a carriage trainable about a vertical axis, and having bearings supporting said gun for elevation on said carriage about a horizontal axis, gear means on said carriage concentric of said elevation axis, a bracket on said gun, a pinion journaled in said bracket having one-half the effective diameter or said gear means and meshing with said gear means, a yoke rotatable by and in synchronism with said pinion, a gimbal pivoted in said yoke on a precession axis lying in a plane normal to said elevation axis, a gyroscope journaled in said gimbal for spinning on an axis normal to said precession axis and leaddetermining means responsive to the precession of said gyroscope.

1a. In combination with a gun, having a carriage and trunnions journalled in said carriage, first gear means fixed to said carriage concentric of said trunnions, second gear means journaledson said gun on an axis parallel to said trunion axis, said first gear means being twice the diameter of, and meshing with said second gear means, a yoke carried by said second gear means, and a gyroscope carried by said yoke for precession about an axis lying in a plane normal to the axis of said second gear means.

15. The combination with a gun movable in train and elevation, a gyroscope mounted to precess about an axis maintained in a vertical plane parallel to the gun bore and having its spin axis normal to said precession axis, means connected with said gun to rotate said precession. axis in said plane about an axis normal to said plane and at an angle equal to twice the angle of gun elevation, and indicating means operated by the precession of said gyroscope. I 16. In combination with a gun mounted to have mutually perpendicular train and elevation axes, a gyroscope mounted on said gun and having a first spin axis, a second precession axis normal to said spin axis and a third axis of elevation normal to said precession axis andparallel to said gun elevation axis, connections rotating said precession axis about said third axis at a predetermined multiple of the rate of gun elevationQ means rotated by and in synchronism with. the resulting precession of said gyroscope about said second axis,- including follow-up contact means and a sector in contact with said contact means and rotatable on anaxis concentric therewith, said sector having opposed insulated contacts, a differential, follow-up motor means reversely controlled by said contact means and sector, said motor operating one side of said difierential, means operating a second side of said differential by and in accordance with movement of said gun about its train axis, and a shaft driven by the center of said differential and connected to operate said sector. I

17. In combination with a gun trainable and elevatable about mutually perpendicular axes, a gyroscope, means mounting said gyroscope for pivotal movement about mutually normal first and second axes, said second axis being normal to the spin axis of said gyroscope, all said axes being concurrent at a point, and means connecting said gun and mounting means to positively rotate said gyroscope about its said first axis in a corresponding direction and at an angular rate equal to twice the angular rate of change of elevation of said gun, whereby said gyroscope is induced to process about said second axis through an angle proportional to the angle of approach of a target as the gun is moved to fire on the target.

18. In combination with a gun mounted for elevation on a trainable base to follow a moving target, a gyroscope, means mounting said gyroscope on said gun for pivotal movement about mutually normal first and second axes, said second axis being normal to the spin axis of said gyroscope, all said axes being concurrent at a point, said first axis bein fixed parallel with the elevation axis of said gun, and means responsive to change of elevation of said gun to rotate said gyroscope about said first axis at a rate equal to twice the rate of change of elevation of said gun as the latter is moved to follow said target, whereby said gyroscope is caused to precess about said second axis.

19. In a device for directing a gun,'a speed arm pivoted at one end for angular movement about a first axis normal to said arm, an element on said arm and adjustable therealong to vary its distance from said axis in accordance with speed of a target, a directional arm pivoted at one end for angular movement about a second axis in spaced parallel fixed relation with said first axis, said axes vbeing spaced a distance proportional to time of flight to predetermined range, of a projectile from the gun, a pivotal connection between said element and the other end of said directional arm, a gyroscope, means mounting said gyroscope in neutral equilibrium for precessibh 151601 5 5 #111171 'axls, means mtatinz saidmounting means about a fourth :axis inormal :to

said-precession axis, at a rate equal to.-twice the rate of gun elevation, meanszrespansiveio precession 01 :said gyroscope 'to pivot. :said :speed arm about 'said .first :axis', .a :sight, andmeans angularly'moving said sight melatlvelyto the-gun in accordance with angular movement of said directional arm.

HERBERTK. WEISS.

REFERENCES GI'IED The following references are of record in "the file of this patent:

Number-f Number 16 Name 1 Date Tear et a1; July 30, (1948 Tear et al. Sept. 3,1946 Freeman June 10, 1947 Hammond et*a1.1. Jan. 6, 1948 Moore :et a1. May 4, 51948 Burley et a'1..1 1 Mal-.15, 1949 Johnson -1 Apr. "19, 1949- Meachum 1 May,.24, 19.49 Weiss July 19, 1949 Bernart et a1. Aug. 23, .1949 Moore: 1 Apr. 3, 1951 Johnson Apr.- 24, 1951 Hammond 1 June .19, 1951 FOREIGN PATENTS Country Date 7 Genmany- 1 Fem-6,1928 Germany 12.1.1- Dec. 19-, .1934

France Jan. 16, 1939 

